For example, an interior permanent magnet motor having a plurality of permanent magnets embedded in a rotor core is used as a motor for a compressor to be used in a refrigeration apparatus or an air conditioning apparatus. The plurality of permanent magnets are each inserted into a corresponding magnet receiving hole formed in the rotor core.
In such a motor for a compressor, a lubricating oil in an airtight container of the compressor enters each of the magnet receiving holes so that the permanent magnets may easily be moved. Further, as a direct factor, an electromagnetic force from a stator acts on each of the permanent magnets so that the permanent magnets may be moved inside the magnet receiving holes. As a result, vibration and noise may be generated due to such movement of the permanent magnets.
In view of this, in a motor disclosed in Patent Literature 1, a pair of permanent magnets separated from each other are inserted into each of the magnet receiving holes of the rotor core. In the motor, due to the electromagnetic force from the stator, the pair of permanent magnets are pulled inside the corresponding magnet receiving hole in directions away from each other. Therefore, it is intended that, even when the lubricating oil enters each of the magnet receiving holes during an operation of the compressor so that the permanent magnets may easily be moved, each of the permanent magnets is not moved inside a slot in a reciprocating manner to suppress the above-mentioned vibration and noise.